Apparatus and process for cleaning collapsible tubes



May 6, 1969 3,442,707

APPARATUS AND PROCESS FOR CLEANING GOLLAPSIBLE TUBES H.S.DZEDZEJ SheetFiled July 21, 1965 m 2 ll? IAVIVENTOR. Afenryafi'fize 26/ ATTORNEYS y6, 1969 H. s. DZEDZEJ 3,442,707

APPARATUS AND EROCESS FOR CLEANING COLLAPSIBLE TUBES Filed July 21, 1965Sheet 2 of 2 6; 07 J DRAIN k )sowem I Z I v 6/ 1 2 IAIRHEATER INVEN OR.flew/761026 zeg ATTORNEYS United States Patent 3,442,707 APPARATUS ANDPROCESS FOR CLEANING COLLAPSIBLE TUBES Henry S. Dzedzej, Wallingford,Pa., assignor to A. H.

Wirz, Inc., Chester, Pa., a corporation of Pennsylvania Filed July 21,1965, Ser. No. 473,598 Int. Cl. B08!) 9/00 US. Cl. 134-24 3 ClaimsABSTRACT OF THE DISCLOSURE A process and device for cleaning theinterior of a collapsible tube having a cap attached at one end in whichthe tube is supported on a mandrel having a shoulder adjoining ashoulder in the tube and having one or preferably a plurality oforifices through the shoulder, the mandrel having a shank which has aclose clearance to create a flow of solvent parallel to the size of thetube.

This invention relates to an apparatus and process for cleaningcollapsible tubes and more particularly it relates to an apparatus andprocess for removing metal particles within the interior of such tubes.

In the production of metal collapsible tubes, fine metal particles areoften introduced into the interior of the tube during its formation andin subsequent machining operations especially in the area of the tip ofthe tube where a cap is to be secured. Data has been compiled andstandards have been set with respect to the level of metal particlespermissible in tubes where the contents of the tube must of necessity befree from foreign matter such as ophthalmic ointments. Acceptable limitsfor such ointments have been placed at a level not exceeding 50particles of over 50 microns in size in any ten tubes of ointment withno one tube containing more than 8 such particles.

These limitations on foreign matter are very restricted and thus it isnecessary to provide a system for the effective and eflicient cleaningof tubes after they have been formed and before they are filled in orderto meet these standards.

Accordingly an object of this invention is to provide a process for theeffective and efiicient cleaning of collapsible tubes.

It is a further object of this invention to provide a system forcleaning capped collapsible tubes suitably made of extruded metal to ridthem of substantially all foreign particles.

It is a further object of this invention to provide a system forcleaning collapsible tubes that forces a solvent into a thin stream downalong the interior surface of the tubes, expels the solvent out the openend of the tube and subsequently drys the interior of the tube toprepare it for the filling operation.

Another object ofthis invention is to provide a nozzle, which supportsthe tube during the cleaning operation, and forces the cleaning solventinto the interior of the tube, down the sides of the tube and out itsopen end.

Another object of the-invention is to provide a nozzle as a supportingelement that will allow drainage of the solvent from the tube andprevent the reverse flow of solvent up the outside of the tube duringthe cleaning operation.

Further objects and advantages will be readily apparent from thefollowing description of the drawings:

FIGURE 1 is a schematic view showing diagrammatically an assembly ofelements employed in carrying out my method for cleaning collapsibletubes.

FIGURE 2 is a top view showing the tip of the nozzle and the outletorifices with the surrounding tube wall in section.

FIGURE 3 is a sectional view taken along the lines 33 of FIGURE 2showing the nozzle with a capped tube in position for cleaning.

FIGURE 4 is a sectional view taken along the lines 4-4 of FIGURE 3omitting the tube and showing the drainage channels in the side of thenozzle.

FIGURE 5 is an electrical diagram depicting schematically the necessarycircuit for operating the various assembly elements shown in FIGURE 1 inthe proper sequential order.

Essentially the invention consists of introducing a solvent underpressure through a nozzle into the interior of a capped collapsible tubenear its capped end, forcing it down a narrow space provided between thetube and the shank of the nozzle and out the open end of the tube. Byrestricting the passage a parallel flow of fluid along the insidesurfaces of the tube is created, which effectively flushes all metalparticles out the bottom end of the tube. After flushing, the solvent ispermitted to drain out of the nozzle and subsequently a blast of air isemittedfrom the nozzle and into the tube to rid it of any excess solventand to dry it in preparation for filling.

Collapsible tubes have conventionally been cleaned with suction devicesas disclosed in US. Patent No. 2,637,872. However, the suction needed torid the tube of all extraneous matter is often so great that it causesthe tube to collapse, thus damaging it and rendering it useless. It istherefore an important aspect of this invention that applicant hasprovided a novel cleaning process without resorting to the use ofsuction. By forcing the air through the tube according to thisinvention, no dam age is inflicted upon the tube itself.

Ultrasonic degreasing has also been used as a cleaning technique but inthis method the tubes must be immersed or dipped into a solution.Consequently they must be cleaned by this method before decoration hasbeen applied to the tube, as such a cleaning process would destroy anylacquer or decorative coating thereon.

This invention, however, provides a cleaning system which can be appliedat the very last stage of the tubemaking process after all the milling,decorating, capping and other steps have been completed subsequent tothe extrusion of the tubes. In ultrasonic degreasing, metal particlesmay be introduced during these subsequent steps of capping anddecorating but in applicants process this is prevented because theseoperations have already been performed on the tube before it is cleaned.

Referring now to FIGURE 1, there is shown schematically a system forcarrying out the process of this invention. The tubes supporting mandrelor nozzle cleaning device is generally indicated as 10. A tube 11 havinga cap 12 affixed thereto, has a side wall 11' and a shoulder 11 with itsbottom end open, is in position for cleaning over the mandrel or nozzle10. Above the tube is a guard plate 13 which acts as a stop to preventthe tube from being wholly displaced olf the mandrel when the solvent isintroduced under pressure. The plate is also provided with sides 14which help to prevent the spraying of solvent out of the area in casethere is a defect in the tube. These sides on the guard help to containany free solvent vapors. Th guard, of course, will have to be removedbefore the tube is inserted on the mandrel and then replaced. Thismovement may be manually controlled or suitably automatically controlledby a switch coordinated with the starting of a cleaning cycle.

In FIGURE 3, the tube and mandrel are shown in greater detail, themandrel consisting of a shank 20 having a central orifice 21communicating with a plurality of smaller orifices 22 at the upper endof the mandrel, thus forming the nozzle end. This end is provided with ashoulder 23 in order to position the tube properly with respect to themandrel and is slotted at 24 to allow the solvent to drain out thebottom end of the tube. At a lower point but before the bottom of theskirt of the tube is reached, the mandrel is relieved at 25. Betweenthis point 25 and the top edge of the mandrel, the clearance between thetube and the shank of the mandrel should be greater than .005 inch butshould not exceed .015 inch except at the locations where the slots 24exist in the side of a mandrel. This allows the flushing solvent toessentially flow parallel to the tubes inner wall providing a scrubbingaction which detaches and removes any foreign particles. It was found,however, that if this clearance was carried along the entire length ofthe tube that the flushing solvent tended to return up the outside ofthe tube at the botom end. This has been successfully avoided byproviding an additional clearance or relief starting at 25 part of theway down the shank of the mandrel. At this point there should be atleast a clearance of .030 inch between the mandrel and the lower portionof the skirt of the tube, the mandrel then having preferably the samediameter as the inside of the drainage channels 24.

It is important also that the collapsible tube 11 be capped with asuitable cap 12 so that the flow of solvent will be directed in areverse direction down the space between the mandrel and the inside ofthe tube. The presence of the cap additionally acts to prevent the tipof the tube from being damaged against the guard plate, if the tube ispushed up into it by the force of the flow of solvent. Applicant hasthus provided a cleaning element that will effectively flush the insideof the tube without harm to its structure or its outside surface.

Referring again to the flow diagram of FIGURE 1, a source of solvent 28,suitably trichloroethylene or Dupont Freon, is withdrawn through line 29by pump 30 which continuously pumps to a pressure relief valve 31 thatreturns the solvent to the source when the system is not dischargingsolvent through the nozzle 10. During discharge, the solvent passesthrough a filter or series of filters 34, the pressure of the fluidbeing indicated by gauge 35. The minimum pressure for the solvent shouldbe at least 50 p.s.i. Solenoid valve 36 controls the discharge of thesolvent as shown in the electrical diagram in FIGURE 5. When the valveopens, the solvent passes through a horizontal check valve 37 whichprevents the entrance of air into the line and/ or prevents a backwashof the solvent. The solvent then passes up and out the nozzle at itsupper end. During this discharge, solenoid valve 38 remains closed sothat all of the solvent will pass out through the nozzle.

When it is desired to drain the solvent, the valve 36 closes,interrupting the flow of solvent and the valve 38 opens permitting anysolvent remaining in the lines to flow by gravity out of line 39 intocontainer 42. This container surrounds the lower end of the mandrel toalso catch the solvent that is expelled out of the bottom end of thetube. All of the solvent then empties by gravity flow through line 43into sump container having a cover 41. Included in the container is afloat switch 44 which when actuated by the level of spent solvent in thecontainer, energizes a return pump 45 sending the spent solvent througha reconditioning filter 46 back to the solvent source 28 to be usedagain.

After the solvent has been flushed through the tube and given suflicientamount of time to drain, air is introduced into the system through line47 passing through an optional heater 48 to warm the air as an aid tothe drying operation. The air then passes through a regulator 49 and afilter 50 to remove any trace of foreign particles. The flow of air tothe system is controlled by solenoid valve 51, which when activatedsends the air through check valve 52 up and out the nozzle and down thespace between the tube and the mandrel to blow out excess solvent andmetal particles and to dry the tube.

A suitable exhaust system is provided as generally indicated at 53 inorder to remove any excess solvent vapors which may be present in tharea.

Referring now to the electrical diagram in FIGURE 5 there is shown adouble pole switch which provides the energy to operate the system. 61is a microswitch, which is closed mechanically when the guard plate 13is moved to an operative position. This closed circuit then energizetimer 62, and at the same time energizes solenoid valve 36 throughnormally closed switch 63 thus allowing solvent to flow through thenozzle. Additionally, indicator light 64 is energized to indicate thatthe flushing stage is in operation. After the timer 62 reaches apredetermined point and runs out, usually 1 to 2 seconds after thesolvent begins flowing, the timer opens normally closed switch 63,deenergizing solenoid valve 36, thus closing it and interrupting theflow of solvent. Simultaneously the timer 62, having run out, alsocloses normally open switch 65 so that it will now energize timer 66 andat the same time energize solenoid drain valve 38 through normallyclosed switch 67. Indicator light 68 indicates that the draining stagein the operation has been reached. After this timer reaches itspredetermined point and runs out, usually two seconds after the fiow ofsolvent has been interrupted, the timer 66 opens normally closed switch67, deenergizing solenoid valve 38, thus closing it. Simultaneously thetimer 66, having run out, also closes normally open switch 70,energizing timer 71 and at the same time energizing solenoid air valve51 through normally closed switch 72 to start the flow of compressed airat about p.s.i. through the nozzle. Additionally, indicator light 73indicates that the drying stage in the operation has been reached.Optionally the air heater 74 can be used to heat the air by manuallyclosing switch 75. After this timer 71 runs out it opens normally closedswitch 72 deenergizing and closing the air valve 51 thus completing thecleaning cycle.

I have shown only one mandrel or nozzle for ease in explaining the fiowdiagram, but it is apparent that the system can equally be applied to awhole bank of nozzles for the cleaning of a plurality of tubessimultaneously. Preferably they could be provided with an automaticsystem that would place all the tubes on multiple flushing heads ormandrels, place the guard plate over the top of them and subsequentlylift them off after the tubes had been cleaned. Instead of placing aseries of tubes simultaneously on to multiple flushing heads, acontinuous system using one or a number of heads could also be usedaccording to the process of this invention.

In view of my invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of myinvention without copying the structure and process shown, and Itherefore claim all such insofar as they fall within the reasonablespirit and scope of my claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A process for cleaning the interior of a collapsible tube having acap attached at one end, having a shoulder, having a side wall and openat the end opposite to the cap, which comprises supporting the tube on amandrel having a shoulder at one end adjoining the shoulder in the tubeand having orifices at the shoulder, the mandrel having a clearance fromthe interior of the side wall of the tube at a plurality ofcircumferentially spaced points of between 0.005 and 0.015 inch, forcinga solvent through the orifices and down the space between the tube andthe mandrel to create a flow of solvent parallel to the sides of thetube, allowing the solvent to drain out of the space between the tubeand the mandrel, and forcing heated air under pressure through theorifices and down said space to remove excess solvent and to dry theinterior of the tube.

2. A device for cleaning a collapsible tube having a.

cap attached at one end, a shoulder, a side wall and an opposite openend, comprising amandrel for supporting said tube having a shoulder atone end, having a cylindrical shank which has a clearance from theinterior of the side Wall of the tube to be placed thereon at aplurality of circumferentially spaced points of between 0.005 and 0.015inch, said shank having a plurality of orifices one of which is centralfor the supply of a cleaning fluid opening at the shoulder, and saidshank being relieved near the open end of the tube but above the openend of the tube to provide a clearance of at least 0.030 inch betweenthe sides of the mandrel and the interior surface of the bottom end ofthe side wall of said tube.

3. A device according to claim 2, including a plurality References CitedUNITED STATES PATENTS 4/1945 Weir l3424 X 7/1945 Cozzoli 134152 X 10DONALL H. SYLVESTER, Primary Examiner.

ARTHUR D. KELLOGG, Assistant Examiner.

US. Cl. X.R.

of longitudinally extending channels in the side of the 15 134-30, 37,50, 152, 199

